Seat fold actuator

ABSTRACT

An actuator configured to actuate a member. The actuator optionally including capabilities for storing and releasing kinetic energy. The actuator being suitable for use in any number of environments, including but not limited to facilitating seat folding operations.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to seat fold actuators.

2. Background Art

Actuators and triggers are devices that cause an apparatus to operate.Latches are devices that are used to grasp or lock an object, as with acatch and a lever, or the like. An actuator may be used to release orengage a latch. Some actuators may be remotely connected to a latch toallow for operation of the latch from a distance.

Latches are used in a wide variety of applications. For example, latchesmay be provided as a part of a machine, on building doors or windows, orin vehicles. Latches that can be reset have the advantage that they canbe used repeatedly. One way to provide a latch that can be reset is toprovide an actuator that operates a motor and gear reducer to releasethe latch by forward rotation of the motor and reset the latch byreverse rotation of the motor. While this approach is effective, thecost of a motor and gear reducer may be uneconomical in manyapplications.

In some applications, it may be desirable to provide a manual actuatorand a power actuator for a latch that may be alternatively used tooperate the latch. Dual mode actuators may be provided to allow a latchto be manually operated or power operated. One problem with such dualactuation latches is that one mode of actuation may interfere with theother mode. In addition, resetting the dual mode actuator may becomplicated if both modes of actuation are not accommodated by the resetmechanism.

One exemplary application for a dual mode remotely actuated latch is avehicle seat back folding apparatus. Vehicle seat backs may be foldedover the seat base to facilitate ingress and egress. Prior art actuatorshave been developed that use a motor that drives a gear reducer in onedirection to release a latch and driven in the opposite direction toreset the actuator for reuse after the latch is engaged. Seat foldinglatches may also be specified to be manually actuated in the event thata user wishes to operate the latch manually or if power is not availablefor the power actuation system. While these types of systems have beendeveloped, the cost of the motor and gear reducer may make such systemsuneconomical.

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention is pointed out with particularity in the appendedclaims. However, other features of the present invention will becomemore apparent and the present invention will be best understood byreferring to the following detailed description in conjunction with theaccompany drawings in which:

FIG. 1 illustrates a vehicle seat in accordance with one non-limitingaspect of the present invention;

FIG. 2 illustrates one way of connecting a seat back to a seat base inaccordance with one non-limiting aspect of the present invention;

FIG. 3 illustrates a trigger assembly in more detail in accordance withone non-limiting aspect of the present invention;

FIG. 4 illustrates a folded over seat position in accordance with onenon-limiting aspect of the present invention;

FIG. 5 illustrates a flipped forward seat position in accordance withone non-limiting aspect of the present invention;

FIG. 6 illustrates an assembly view drawing of the trigger assembly inaccordance with one non-limiting aspect of the present invention;

FIGS. 7 a-9 b illustrate operation of the trigger assembly in accordancewith one non-limiting aspect of the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT(S)

Referring to FIG. 1, a vehicle seat 10 is illustrated that has a seatback 12, a seat base 14, and a trigger assembly 15. An actuator 18 isillustrated as being attached to the seat base 14. However, it should beunderstood that the actuator 18 could be secured to another location onthe vehicle or seat support structure. A latch lever 20 is connected tothe actuator 18 by a Bowden cable 22, or link. The Bowden cable 22includes a sleeve 24 that encloses a wire 26 so that the wire 26 isaxially moveable relative to the sleeve.

The wire 26 connects to a trigger plate 27 such that actuation of thewire 26 in the downward direction causes the trigger plate 27 to move ina counter-clockwise direction and to over come spring biasing providedby a chaser spring 29 in an opposite, locking direction. A power platewire 31 connects a power plate 33 to the latch lever 20 such that apower plate spring 25 instigates counter-clockwise rotation of a powerplate 33 in an actuation direction in order to cause the latch lever 20to pivot in similar counter-clockwise manner about pivot 46. A resetwire 35 connects to power plate 31 and can be tensioned with rotation ofthe seat back 14 in order to facilitate resetting the power plate 31, asdescribed below in more detail.

First and second mirroring wires 37 and 39 actuate mirroring features onan opposite side of the seat 10 so as to perform mirroring operationsassociated with actuating a mirroring latch lever (not shown). Themirroring operations essentially facilitate releasing the opposite sideof the seat in a manner similar to the illustrated side of the seat, butoptionally without a second trigger assembly 15.

Referring to FIG. 2, one type of hinge mechanism is shown in greaterdetail in an exploded perspective view that shows one way of connectingthe seat back 12 to the seat base 14. It should be understood that othertypes of hinge mechanisms may be adapted to include the latch actuatorsystem of the present invention. A pair of seat base plates 36 areconnected to a seat back support bracket 38 by means of a pivot pin 40.Pivot pin 40 is received in a hole 42 that extends through the seat baseplates 36, seat back support bracket 38 and bracket 32. A spring bracket44 retains seat spring 30 and interconnects the seat spring 30 to thepivot pin 40. The latch lever 20 shown in FIG. 1 is connected to a leverpivot pin 46.

The latch lever 20 is secured to the lever pivot pin 46 which is in turnsecured to a latching follower 56. The seat back support bracket 38includes a step 58 that is engaged by the latching follower 56 when theseat is in its latched position. After the seat is unlatched, thelatching follower 56 follows an arcuate cam surface 60 on the supportbracket 38 as the support bracket 38 pivots about pivot pin 40 into aposition where a seat back 12 is folded over the seat base 14.

Referring now to FIGS. 3-4, the trigger assembly 15 is described withreference to the embodiment of the invention described above withreference to FIGS. 1 and 2. FIG. 3 is an enlarged illustration of aportion of the apparatus described with reference to FIG. 1 that iswithin the oval denoted FIG. 3 in FIG. 1. In FIG. 3, the apparatus isshown in its latched condition with the seat back support bracket 38held in a vertical, rearwardly inclined orientation and is fixedrelative to the seat base plates 36. In this position the latch lever 20is in its retained position.

A cable sleeve bracket 64 secures the sleeve 24 to seat base 14 or othersupporting structure. seat spring 30A handle 70 is provided at theopposite end of the latch lever 20 from the lever/cable anchor 66. Thehandle 70 is intended to be grasped directly or indirectly by a personfor manually manipulating the latch lever 20. The latch is lifted tocause the latching follower 56 to clear the step 58 and seat back 12 tomove forwardly with the force applied by the seat spring 30, therebyallowing the seat back 12 to rotate to a folded over position as thelatching follower 56 follows the arcuate cam surface 60.

While not shown, the handle 70 may be provided with an enlarged handlecover to make the handle 70 easier to grasp and to provide a finishedappearance. As shown in FIG. 3, a slack portion 72 may be provided inthe wire 39 to allow the handle 70 to be easily lifted withoutencountering resistance from the seat spring 30 mirroring element (notshow) to which the wire 39 is connected. The extent of slack is somewhatexaggerated as shown for illustrative purposes.

Referring to FIG. 4, actuation of the latch 20 is illustrated in eithera manual or power mode. In the manual mode the lever 20 may be manuallygrasped and moved from the position shown in phantom lines to theposition shown in solid lines. When the latch lever 20 is lifted, thelatching follower 56 disengages the step 58 as previously described.Alternatively, the latch may be power actuated upon triggering theactuator 18. The actuator 18 may comprise a shape memory alloy trigger,a solenoid or other actuator that is capable of exerting a tensioningforce on wire 26. In the embodiment illustrated in FIG. 4 the actuator18 exerts a pulling force on the cable that pulls the trigger plate 27in a counter-clockwise direction. This movement causes the triggerassembly 15 to move from a loaded position to a fired position whereinthe trigger plate 27 triggers the power plate 33 to pull upwardly on thewire 31, which thereby pulls upwardly on the latch lever 20 to actuatethe latch lever 20 from the retained position to the released position.

When the lever actuator 20 is rotated about the pivot pin 46 from theretained position to the released position the latching follower 56disengages the step 58 as previously described. When the latchingfollower 56 clears the step 58 the seat back support bracket 38 movesfrom the position shown in phantom lines in FIG. 4 along the curvedarrow path to the position shown in solid lines in FIG. 4. The seatspring 30 drives the seat back 12 and its associated support bracket 38into the folded over position.

Optionally, as shown in FIG. 5, the seat 10 may automatically flipforward to the illustrated stadium seat position (folded forwardposition) once the seat back 12 reaches the folded over position. A seatbase actuator system 67, or other arrangement, may be included tofacilitate such movement. The seat base actuator system 67 may include acable or other feature (not shown) connected to the seat back 12,support 38, or other feature in the system 10 such that actuation of theseat back 12 to the folded down position allows the seat base actuatorsystem 67 to then flip the seat back 12 and seat base 14 to the stadiumor flipped forward position shown in FIG. 5.

As the seat back 12 folds to or is folded up from the folded position(fold flat, flipped forward, etc.), the reset cable 35 tightens from itsslack position to rotate the power plate 33 from its released position(FIG. 4) to its loaded position (FIG. 3). This movement resets thetrigger assembly 15 such that the power plate 33 is loaded and ready totrigger rotation of the lever latch 20 in response to triggering of thetrigger plate 27. A reset mechanism 68 may be included on the seat baseactuator system 67 to facilitate tensioning the reset cable 35 or someother mechanism may be similarly employed.

FIG. 6 illustrates an assembly view drawing of the trigger assembly 15in accordance with one non-limiting aspect of the present invention. Thetrigger assembly 15 may include the trigger plate 27 on one side of areference plate 80 and the power plate 33 on an opposite of the samesuch that both plates are configured to rotate coaxially about a centralportion 82 of the reference plate 80. Each of the reference plate 80,trigger plate 27, and power plate 33 may include common apertures 86-90for receiving a ball bearing 94-98. The apertures 86-90 on each platemay be arranged relative to each other such that they cooperate tocontrol actuation of the trigger assembly 15 from the loaded to firedpositions.

A chaser spring 29 may be attached to the reference plate 80 and thetrigger plate 27 such that the chaser spring 29 causes the trigger plate27 to rotate in a clockwise direction relative to the reference plate80. A power spring 102 may be attached to the reference plate 80 and thepower plate 33 such that the power plate spring 25 causes the powerplate 33 to rotate in a counter-clockwise direction relative to thereference plate 80. As described below in more detail, thecounter-clockwise rotation of the power plate spring 25 may be used toactuate the power plate 33 and the connected latch lever 20 from theretained position (loaded position) to the released position (firedposition). Similarly, the clockwise rotation of the chaser spring 29 maybe used to return the trigger plate 27 from the fired position to theloaded position.

FIGS. 7 a-9 b illustrate the interaction of ball bearing 94 with one ofthe corresponding apertures 86 in accordance with one non-limitingaspect of the present invention. FIGS. 7 a-7 b relate to the loadedposition, FIGS. 8 a-8 b relate to the fired position, and FIGS. 9 a-9 brelated to returning from the fired to loaded position. The loadedposition includes the trigger assembly 15 storing kinetic energyassociated with a cocked or otherwise flexed power plate spring 25 suchthat the ball bearing 94 is disposed partially within the aperture 86 ofthe power plate 33 such that the power plate 33 is unable to move in thecounter-clockwise direction. The fired position relates to the releasingof the stored energy and the counter-clockwise rotation of the powerplate 33, i.e., the releasing of the power plate spring 25 to rotate thepower plate 33 and thereby actuate the latch lever 20.

From the loaded position, the fired position may be obtained withmovement of the trigger plate 27 in a counter-clockwise direction, suchas with actuation of the trigger wire 26. This movement aligns theaperture 86 of the trigger plate 27 with the corresponding aperture 86of the reference plate 80. Because the power plate 33 is under forcefrom the power plate spring 102, the power plate is urged against theball bearing 94 such that once the trigger plate 27 is aligned with thereference plate 80, the ball bearing 95 travels along an incline 106 andinto the apertures 86 of the reference plate 80 and trigger plate 27,thereby freeing the power plate 33 to move in the counter-clockwisedirection, which as described above actuates the latch lever 20 from theretained position to the released position.

From the fired position, and once tensioning on the trigger wire 26 isremoved or decreased below the force of the chaser spring 29, the chaserspring 29 forces the trigger plate in a clockwise direction such that anincline 108 on the trigger plate 27 forces the ball bearing 94 in adownward direction, once the power plate 33 is properly aligned toreceive the ball bearing 94. The power plate 33 may receive the ball 94if it is reset, i.e., returned to the positioning shown in FIG. 7 a thatpermits the ball bearing 94 to be disposed within a portion of the powerplate 33. The power plate 33 may be reset in any manner, includingtensioning or other tightening of the reset wire 35, such as by theflipping of the seat back 14 and/or seat base 12 described above.

In the illustrated embodiments, the seat backs 12 are disclosed asexamples. The seat back may be more generically referred to as a latchedmember. Other types of latched members may include a seat base, acombination of a seat base and seat back, a headrest, a flat screenvideo display, a compartment cover, a glove box door, a hood, a decklid, a seat back tilt adjustment armature, and the like. Another examplein which more than one latched member is controlled by the latch andtrigger is that of a seat back that folds over a seat base, and then thefolded over seat is tumbled forward for storage, ingress, and egress.With any of those arrangements the trigger is electrically actuated anda movement of the latched member is executed to reset the trigger.

As required, detailed embodiments of the present invention are disclosedherein; however, it is to be understood that the disclosed embodimentsare merely exemplary of the invention that may be embodied in variousand alternative forms. The present invention fully contemplates itsapplication in any number of environments, including those associatedwith U.S. patent application Ser. No. 11/278,295, filed Mar. 3, 2006,the disclosure of which is hereby incorporated in its entirety. Thefigures are not necessarily to scale, some features may be exaggeratedor minimized to show details of particular components. Therefore,specific structural and functional details disclosed herein are not tobe interpreted as limiting, but merely as a representative basis for theclaims and/or as a representative basis for teaching one skilled in theart to variously employ the present invention.

While embodiments of the invention have been illustrated and described,it is not intended that these embodiments illustrate and describe allpossible forms of the invention. Rather, the words used in thespecification are words of description rather than limitation, and it isunderstood that various changes may be made without departing from thespirit and scope of the invention.

1. An actuator comprising: a reference plate having one or more apertures for receiving a ball bearing; a trigger plate configured to rotate about one side of the reference plate; a power plate configured to rotate about an opposite side of the reference plate; a chaser spring connected to the reference plate and the trigger plate, the chaser spring configured to rotate the trigger plate in a locking direction; a power spring connected to the reference plate and power plate, the power spring configured to rotate the power plate in an actuation direction; wherein each of the trigger plate and power plate include apertures corresponding with the apertures of the reference plate such that ball bearings received within the apertures are free to move therebetween; wherein the apertures in the trigger plate and power plate each include an incline to force at least part of the ball bearings out of the apertures of the same; wherein the trigger plate and power plate are moveable between loaded and fired positions, the loaded position corresponding with the ball bearings being positioned within the apertures such the ball bearings are located within a portion of the apertures of the power plate that prevents the power spring from rotating the power plate in the actuation direction, the fired position corresponding with the ball bearings traveling along the incline of the apertures of the power plate to a position within the apertures of the trigger plate that permits the power spring to rotate the power plate in the actuation direction; and wherein the chaser spring rotates the trigger plate in the locking direction from the fired position to the loaded position such that the ball bearings travel along the incline of the apertures of the trigger plate to the position within the apertures of the power plate that prevents the power spring from rotating the power plate in the actuation direction if the power plate is reset.
 2. The actuator of claim 1 wherein the power plate and trigger plate are co-axially aligned relative to the reference plate in order to provide coaxial movement of the same.
 3. The actuator of claim 1 wherein the power plate is reset with force in a direction opposite to the actuation direction if the force is greater than a force applied by the power spring in the actuation direction.
 4. The actuator of claim 1 wherein the locking direction is opposite to the actuation direction.
 5. An actuator for a latch assembly comprising: a latched member secured by a latch, the latch having a released position and retained position, the latched member retained by the latch in the retained position and the latched member freed from the latch in the released position; and a trigger assembly connected to the latch and actuatable from a loaded position to a fired position, the loaded position corresponding with the trigger assembly preventing release of kinetic energy stored within the trigger assembly and the fired position corresponding with releasing the stored kinetic energy, wherein the releasing of the stored kinetic energy causes the trigger assembly to actuate the latch from the retained position to the released position.
 6. The actuator of claim 5 wherein the trigger assembly comprises: a reference plate having one or more apertures for receiving a ball bearing; a trigger plate configured to rotate about one side of the reference plate; a power plate connected to the latch and configured to rotate about an opposite side of the reference plate; a chaser spring connected to the reference plate and the trigger plate, the chaser spring configured to rotate the trigger plate in a locking direction; a power spring connected to the reference plate and power plate, the power spring configured to rotate the power plate in an actuation direction so as to actuate the latch from the retained position to the released position; wherein each of the trigger plate and power plate include apertures corresponding with the apertures of the reference plate such that ball bearings received within the apertures are free to move therebetween; wherein the apertures in the trigger plate and power plate each include an incline to force at least part of the ball bearings out of the apertures of the same; wherein the trigger plate and power plate are moveable between loaded and fired positions, the loaded position corresponding with the ball bearings being positioned within the apertures such the ball bearings are located within a portion of the apertures of the power plate that prevents the power spring from rotating the power plate in the actuation direction, the fired position corresponding with the ball bearings traveling along the incline of the apertures of the power plate to a position within the apertures of the trigger plate that permits the power spring to rotate the power plate in the actuation direction; and wherein the chaser spring rotates the trigger plate in the locking direction from the fired position to the loaded position such that the ball bearings travel along the incline of the apertures of the trigger plate to the position within the apertures of the power plate that prevents the power spring from rotating the power plate in the actuation direction if the power plate is reset.
 7. The actuator of claim 6 wherein the latched member is a seat back and the actuator further comprises a seat spring configured to flip the seat back forwardly about a pivot to a folded position if the latch is in the released position.
 8. The actuator of claim 7 further comprising a reset wire connected to the power plate that tightens to reset the power plate as a function of seat folding.
 9. The actuator of claim 7 wherein the trigger assembly is coaxially aligned with the pivot.
 10. The actuator of claim 6 further comprising a trigger wire connected to the trigger plate such that tensioning of the trigger wire causes the trigger assembly to move from the loaded position to the fired position.
 11. The actuator of claim 10 wherein tensioning of the trigger wire rotates the trigger plate against the force of the chaser spring when the trigger plate is in the loaded position such that the apertures of the trigger plate align with the apertures of the reference plate and force applied to the ball bearings by the power plate spring together cooperate to cause the ball bearings to travel from the loaded position to the fired position, and thereby, permit the power spring to rotate the power plate in the actuation direction.
 12. A vehicle seat comprising: a seat base; a seat back; a seat spring configured to rotate the seat back from an upright position to a folded position relative to the seat base; a latch having a released position and retained position, the retained position corresponding with retaining the seat back in the upright position and the released position corresponding with permitting the seat spring to rotate the seat back to the folded position; and a trigger assembly configured to actuate the latch from the retained position to the released position so as to control movement of the seat back from the upright position to the folded position, wherein the trigger assembly is connected to the latch and actuatable from a loaded position to a fired position, the loaded position corresponding with the trigger assembly preventing release of kinetic energy stored within the trigger assembly and the fired position corresponding with releasing the stored kinetic energy, wherein the releasing of the stored kinetic energy causes the trigger assembly to actuate the latch from the retained position to the released position.
 13. The vehicle seat of claim 12 wherein the trigger assembly comprises: a reference plate having one or more apertures for receiving a ball bearing; a trigger plate configured to rotate about one side of the reference plate; a power plate connected to the latch and configured to rotate about an opposite side of the reference plate; a chaser spring connected to the reference plate and the trigger plate, the chaser spring configured to rotate the trigger plate in a locking direction; a power spring connected to the reference plate and power plate, the power spring configured to rotate the power plate in an actuation direction so as to actuate the latch from the retained position to the released position; wherein each of the trigger plate and power plate include apertures corresponding with the apertures of the reference plate such that ball bearings received within the apertures are free to move therebetween; wherein the apertures in the trigger plate and power plate each include an incline to force at least part of the ball bearings out of the apertures of the same; wherein the trigger plate and power plate are moveable between loaded and fired positions, the loaded position corresponding with the ball bearings being positioned within the apertures such the ball bearings are located within a portion of the apertures of the power plate that prevents the power spring from rotating the power plate in the actuation direction, the fired position corresponding with the ball bearings traveling along the incline of the apertures of the power plate to a position within the apertures of the trigger plate that permits the power spring to rotate the power plate in the actuation direction; and wherein the chaser spring rotates the trigger plate in the locking direction from the fired position to the loaded position such that the ball bearings travel along the incline of the apertures of the trigger plate to the position within the apertures of the power plate that prevents the power spring from rotating the power plate in the actuation direction if the power plate is reset.
 14. The vehicle seat of claim 13 further comprising a trigger wire connected to the trigger plate and an electrically operable actuation device configured for tensioning the trigger wire wherein tensioning of the trigger wire actuates the trigger assembly from the loaded position to the fired position, and thereby, actuation of the latch from the retained position to the released position.
 15. The vehicle seat of claim 14 wherein tensioning of the trigger wire rotates the trigger plate against the force of the chaser spring when the trigger plate is in the loaded position such that the apertures of the trigger plate align with the apertures of the reference plate and force applied to the ball bearings by the power plate spring together cooperate to cause the ball bearings to travel from the loaded position to the fired position, and thereby, permit the power spring to rotate the power plate in the actuation direction to cause the latch to actuate from the retained position to the released position.
 16. The vehicle seat of claim 12 wherein the trigger assembly is coaxially aligned with the seat spring.
 17. The vehicle seat of claim 12 further comprising a reset mechanism to reset the trigger to the loaded position as a function of seat folding.
 18. The vehicle seat of claim 17 further comprising a reset wire to move the trigger assembly to the loaded position.
 19. The vehicle seat of claim 12 further comprising a seat base actuator system to fold the seat base and seat back.
 20. The vehicle seat of claim 19 wherein the seat base actuator system is configured to fold the seat back and seat base from a folded over position to a flipped forward position only after the seat spring folds the seat back to the folded over position. 